As an example of a liquid ejection device, an ink jet printer is known. The ink jet printer includes: an ink jet head (a liquid ejection section) ejecting an ink; and a buffer tank (a liquid supply section) arranged above the ink jet head and supplying the ink to the ink jet head.
The buffer tank is connected to four ink tanks through tubes and then receives inks of four colors supplied from the four ink tanks. The buffer tank includes four air-trap chambers corresponding to the inks of four colors. The air-trap chamber for yellow ink is formed in a U-shape having two right-angled corner portions. Further, the air-trap chamber for cyan ink is formed in a U-shape having two right-angled corner portions, along the air-trap chamber for yellow ink.
The ink in the buffer tank is supplied to the ink jet head after the air is separated and removed in the air-trap chamber. The air collected in the upper portion of the air-trap chamber is discharged to the outside through an air discharge section connected to the air-trap chamber.